Problem: $ { \left[\begin{array}{rrr}{4} & {2} & {2} \\ {1} & {-1} & {4}\end{array}\right]-\left[\begin{array}{rrr}{-2} & {0} & {-1} \\ {1} & {-2} & {4}\end{array}\right] = {?} } $
Answer: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rrr}{4}-{-2} & {2}-{0} & {2}-{-1} \\ {1}-{1} & {-1}-{-2} & {4}-{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{6} & {2} & {3} \\ {0} & {1} & {0}\end{array}\right]}$